(iOS) Plane shadow that follows object on flat terrain - Translate but not Rotate.

I have a sphere that moves on a flat terrain by finger swipping. The sphere does not only translate but rotates too.

I was planning to use a plane at ground level with a shadow texture on it. Then parent my sphere to it. Then my "shadow" would follow my sphere like a real shadow (and I'd only be charged 1 draw call in comparison to using a blob shadow - that's my goal).

Of course my "shadow" rotates as my sphere rotates while translating.

I thought of using the same script that controls the sphere translation & rotation on the "shadow", after having removed the rotation-relevant lines of code. So the "shadow" would have a parallel behavior to the sphere, without the rotation.

Then I thought that maybe there is another way, less cpu demanding (supposing that using this 2nd script is a small extra burden for the cpu - and I am trying to avoid that as much as I can).

Any ideas on how to make the "shadow" follow the sphere without rotating, would be deeply appreciated. :-)

Use a script on the shadow that just follows the sphere:

var transformToFollow : Transform;
var offset = Vector3.zero;
private var myTransform : Transform;

function Start () {
    myTransform = transform;

function LateUpdate () {
    myTransform.position = transformToFollow.position + offset;